I also really like and want to call attention to the charting of highway functions, purposes, and logic with that of the public realm:
Consistent (ed. note: for rhetorical purposes one might say 'monotonous' or 'relentless')
Signs and markings (aka regulation)
Contextual (locally defined)
Cultural/Social rules (mores)
One of these operates under the rules of complex, interdependent, and resilience of networks. The other doesn't.